1. Field of the Invention
The present invention relates generally to wheeled trailers for towing behind powered vehicles, and more specifically to a trailer adapted for servicing other motor vehicles (automobiles, light pickup trucks and the like, etc.) at various mobile locations. The present trailer includes rearwardly disposed and vertically adjustable wheels and laterally disposed ramps and lifting means providing for the loading of a motor vehicle onto the trailer for service, and lifting the vehicle for access to and service beneath the vehicle.
2. Description of the Related Art
Motor vehicles are conventionally driven or transported to a central location for mechanical and other service, with the central location providing a base of operations for mechanics and also providing tools, equipment, electrical, hydraulic, and pneumatic power, etc. generally accepted as necessary for such operations.
While such operations work well if the vehicle can be delivered to such a shop, oftentimes it can be difficult to perform such a delivery. The obvious situation preventing ease of delivery is the need for emergency repairs before the vehicle can be driven, as when a fuel pump or ignition system fails, etc. Even when the vehicle may be drivable, it may be extremely difficult for the owner or operator of the vehicle to arrange to deliver the vehicle to a specialized shop for certain repairs, due to shop hours, work hours of the owner, etc.
Also, many companies and commercial concerns operate at least a small fleet of motor vehicles, and particularly with smaller concerns, may not have their own dedicated vehicle shop or maintenance facility. In such a situation, the company must arrange for relatively frequent delivery and pickup of their vehicles to a maintenance facility for even the most routine of tasks (oil changes, tire maintenance and replacement, etc.).
Accordingly, some mechanics have recognized a need for some means of taking the maintenance facility to the location of the vehicle requiring maintenance or repair, rather than the other way around. Some mechanics have formed small businesses operating from a light truck, van, or other suitable vehicle, where the mechanic drives the maintenance vehicle to the location of the motor vehicle requiring maintenance or repair, and performs the maintenance or repair at that location, rather than requiring that the vehicle be driven or transported to a maintenance location.
While such operations have worked out reasonably well in certain limited types of maintenance, the maintenance which may be performed using such a mobile service facility is quite limited. For example, access beneath the vehicle for removal and replacement of an oil filter, etc. may be impossible using such mobile equipment. This greatly limits the type of maintenance which can be performed at the location of the motor vehicle, using such a conventional mobile maintenance facility. Moreover, oftentimes the vehicle requiring maintenance is in a severely limited location, such as an underground parking area where the operator has parked for the work day. It may be quite difficult, if not impossible, to access the vehicle for maintenance in such cramped quarters.
Accordingly, a need will be seen for a mobile service trailer for performing maintenance work upon an automobile or comparable motor vehicle. The present mobile service trailer is of conventional size for convenient towing, maneuvering, and storage, but includes lateral ramps and a pair of opposed chain drive type lifts for positioning a vehicle laterally across the trailer and lifting the vehicle for maintenance beneath the vehicle. The present trailer is an improvement over other such devices, in that the two lifts are positioned toward the forward and rearward ends of the trailer, enabling the trailer to be positioned in a drive through lane laterally across the front or rear of a vehicle, and the vehicle loaded laterally across the trailer by means of lateral ramps. This configuration saves considerable space and requires far less maneuvering in tight quarters.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 3,931,895 issued on Jan. 13, 1976 to Samuel Grimaldo, titled "Collapsible Trailer Hoist," describes a mobile trailer adapted for automobile maintenance. The Grimaldo trailer includes two laterally spaced, longitudinally oriented lift ramps, with further ramps extendible from the rear of the trailer for loading and unloading the vehicle. Hydraulic means are provided for lifting and lowering the lift ramps, and any vehicle positioned thereon. The Grimaldo trailer, with its continuous vehicle lift ramps and scissor type lift mechanism, has considerable more mechanism beneath the vehicle around which a mechanic must work in comparison to the present trailer invention, and moreover the generally medially positioned trailer wheels preclude any means for loading and unloading the vehicle from the side, as provided by the present service trailer invention.
U.S. Pat. No. 4,031,982 issued on Jun. 28, 1977 to Olov H. Lindfors, titled "Device For Mounting Chassis Details Onto An Automobile Body," describes a mobile apparatus for guiding along a vehicle assembly line in an assembly plant. The motor vehicle is raised to a stationary position over the center of the apparatus, with a vertical lift beneath the vehicle providing for lifting an engine assembly or the like into position in the vehicle for installation. No means for towing the Lindfors apparatus, nor for rolling a completed vehicle thereon for maintenance, is disclosed.
U.S. Pat. No. 4,238,114 issued on Dec. 9, 1980 to Pier I. Migliorati, titled "Rocking Platform For The Positioning Of Vehicles Above Ground Level," describes a platform having a dihedral base configuration, upon which a vehicle may be driven or towed. Initially, the vehicle climbs a pair of ramps at one end of the device, and upon reaching the combined center of mass of the vehicle and platform, rocks over to a level position upon the forward portion of the platform. While Migliorati provides wheels for his platform, they are not configured for use as road wheels or for transporting the device over relatively long distances. Rather, the wheels of the Migliorati device are only intended for pushing or pulling the platform around the area of a maintenance shop or the like. In any event, Migliorati does not provide any means for lowering the upper portion of the platform to a level adjacent the underlying surface, nor for positioning a vehicle laterally across the device, as provided by the present invention.
U.S. Pat. No. 4,350,222 issued on Sep. 21, 1982 to Martin T. Lutteke et al., titled "Variable Tread Vehicle," describes a frame for a mobile agricultural vehicle in which the tread (i. e., lateral spacing between wheels) is variable to accommodate different crop row spacing. The Lutteke et al. vehicle is more closely related to the present inventor's parent application in which laterally adjustable wheels were utilized for longitudinal loading of a vehicle upon the trailer, than to the present invention which utilizes lateral loading and in which the wheels do not move laterally relative to the trailer structure.
U.S. Pat. No. 4,394,877 issued on Jul. 26, 1983 to Lance Whyte, titled "Waste Fluid Receptacle," describes a device which may be extended from beneath a service vehicle to beneath another vehicle undergoing maintenance, to collect fluids (used oil, etc.) draining therefrom. The Whyte device provides for only limited maintenance operations and does nothing to lift the vehicle into the air for access to the underside, as provided by the present vehicle mobile service trailer invention. Moreover, the Whyte device is not a trailer, as is the present invention, but rather retracts and is carried beneath the maintenance vehicle.
U.S. Pat. No. 4,445,665 issued on May 1, 1984 to Donald L. Cray, titled "Vehicle Servicing Lift," describes a mobile vehicle service trailer having a pair of elongate longitudinally oriented ramps. The generally centrally disposed wheels of the device include hydraulic means for lowering the trailer frame to the underlying surface, but their location precludes the lateral orientation of the vehicle ramps and vehicle positioned thereon. In contrast, the present service trailer has wheels disposed at nearly the rear extremity of the trailer, thus keeping the sides of the trailer clear in order to provide lateral loading of a vehicle thereon. The result is a much more compact service trailer which may be positioned across the front of a vehicle requiring maintenance, and the vehicle driven or pulled straight across the trailer. This arrangement provides for ease of operation in tightly congested areas, such as parking garages and the like, as well as simplifying the trailer structure.
U.S. Pat. No. 4,724,875 issued on Feb. 16, 1988 to Wendell Baldwin et al., titled "Trailer-Mounted Portable Oil Change And Lubricating System For Vehicles," describes a device having limited vertical lift capability for a vehicle thereon. Baldwin et al. provide a "creeper" type dolly which rides on tracks positioned between the two wheel ramps or tracks for the vehicle, and indicate that a mechanic may lie or recline upon the dolly in order to perform work beneath the vehicle. In contrast, the two opposed chain hoist type lifts of the present service trailer, provide sufficient lifting height for a mechanic to stand beneath a vehicle supported by the lifts. Also, it is noted that the Baldwin device loads the vehicle longitudinally onto the trailer, with the generally centrally disposed wheels of the Baldwin trailer precluding any lateral loading or unloading of a vehicle thereon, as opposed to the lateral loading of the present service trailer.
U.S. Pat. No. 4,772,038 issued on Sep. 20, 1988 to Nelson MacDonald, titled "Expandable Trailer," describes a utility trailer having laterally expandable and retractable side frame members with laterally spaced wheels extending therefrom. The trailer may be narrowed for towing behind a small off road utility vehicle, or may be widened for towing behind a conventional motor vehicle with the off road vehicle being carried thereon. This trailer is more closely related to the trailer of the Lutteke '222 U.S. Patent and to the present inventor's parent application, each of which have laterally adjustable wheels, than to the present vehicle mobile service trailer.
Swiss Patent Publication No. 385,451 published on Mar. 15, 1965 to Pierre Knittel illustrates a stand having a pair of arcuate segments resting upon rollers therein, with each segment having a length of wheel track thereon. A vehicle is driven or rolled upon the two tracks by means of a pair of ramps, and the device is leveled once the vehicle is centered. While the device has rollers, these provide only for movement about a shop floor or the like, rather than being suitable for towing the device on the road. The device of the Swiss Patent Publication thus relates more closely to the device of the '114 U.S. Patent to Migliorati, than to the present vehicle mobile service trailer invention.
Finally, Soviet Patent Publication No. 458,505 published on Mar. 12, 1975 illustrates a mobile automobile hoist or lift. A relatively small trailer has a rearward portion with lift arms foldably extendible therefrom, onto which an automobile may be driven. The automobile is suspended above the underlying surface behind the trailer, when the lift arms are raised. The Soviet device does not provide for the automobile to be positioned across the center of the trailer and does not provide for symmetrical lifting of the vehicle from each side thereof, as in the present vehicle mobile service trailer invention.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.